Fixes for documentation?

Question

In the following code fragments, don't you really mean: pplx::task<http::http_response > resp ?

(The closing > is missing.)

And once you have defined "resp", why use "r" from then on?

I see this code in http://msdn.microsoft.com/en-us/devlabs/hh976887.aspx

http::http_client client("http://localhost:80");
   pplx::task<http::http_response resp =      
         client.request(methods::GET, "/foo.html");

Here, the ‘resp’ task provides us a placeholder for a value that will be available in the future.

Once you have a task, you need to (eventually) get a value out of it. Since it is possible that the operation finishes so fast that the value is available immediately, it may be reasonable to ask the task whether it is “done” or not:

bool done = r.is_done();

Answer 1

Andrew,

Thank you for taking the time to scrutinize our stuff to this level of detail! I will open a documentation bug on this.

Niklas

Answer 2

If possible, please review the actors documentation at:

http://msdn.microsoft.com/en-us/devlabs/hh975426.aspx

I was trying some of the code samples, and it seems that some functions on the header files have different signature/names that those on the samples. For example, in the code below, the actors::accept signature seems to differ from the .h file and I could not find (neither could VS11) an actors::ActorInitEvent  in the references.

class Hello : public actors::actor
{
public:
    Hello() {}
    actors::actor *factory() { new Hello(); }
 
protected:
    void initialize(actors::ActorInitEvent e) { } 
 
    virtual void execute() {
      std::string name;
      accept(name).then([=](std::string &name) {
        std::cout << "Hello, " << name << "!" << std::endl;
        Done();
      }); 
    }
};

Thanks,

Fernando

Answer 3

Yep, that's another problem. The documentation that is installed along when you unzip the samples is better, but it still has the accept(name) error, which should be accept<std::string>() instead. ActorInitEvent was "init_reason" to have the right casing and better describe its purpose.

While we address these issues for the next release, I recommend looking at the code in the BlackJackServer_Actors sample. That code really does compile... :-) It don't think it uses checkpointing or the choice function anywhere, but most aspects of the actors library are illustrated.

Niklas

Answer 4

In case it is not clear -- the installed docs are available from the readme.htm file at the top level of the extracted ZIP file.

Niklas

Answer 5

Ok, I'll study by the installed docs and the BlackJack project.

Thanks a lot for you help!

Fernando

Answer 6

One more slight issue with the original example. Visual Studio doesn't care for this line

pplx::task<http::http_response resp =  client.request(methods::GET, "/foo.html");

The second argument needs to be a wide string

pplx::task<http::http_response resp =  client.request(methods::GET, L"/foo.html");

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